New Nitrox Diver question: Must I purchase a Gas Analyzer?

[Bubbletrubble]

For the typical recreational diving that I do, I'm an advocate for analyzing a nitrox fill once...with a properly calibrated analyzer...and then marking the tank with a clearly identifiable label indicating O2 percentage.

I've seen some people who have gone to the trouble of having their tanks O2-cleaned and festooning their tanks with nitrox stickers, yet they fail to mark their tanks with the analyzed O2 percentage and then flirt with the MOD of mix on their subsequent dive. That's pretty silly, if you ask me.

I've also seen people wearing 3 different dive computers who fail to do a comprehensive functional pre-dive test on their regulators/BCD or will continue to dive with a busted SPG. Human beings are funny.

Even for experienced divers, it's a good idea to periodically review your list of pre-dive checks to see whether any improvements can be made.

 

[conway400]

What about picking up a nitrox tank that you intend to use with air tables (the added safety - not the deeper/longer benefits)? Do you double check then? Is there a real need to?

 

[tstormdiver]

What about picking up a nitrox tank that you intend to use with air tables (the added safety - not the deeper/longer benefits)? Do you double check then? Is there a real need to?

Personally, I would not, but that is my opinion. You never know if a mistake in the mixing has been made. If it is a "hotter" (higher % of O2) mixture than you anticipate for the depth you are diving (ie. excedes the MOD), then you may have a problem.

 

[MX727]

What shop were you at in Bonaire?

The procedure we followed at Divi was to check our tanks and on the tank we wrote our two digit diver number, %, and MOD. So, if you weren't aware of that procedure, you would see: 41 33% 107 written on the tape. To you, it would look random, but it wasn't.

 

[scjoe]

Every dive op I've used required that we test the tanks in front of them. I can't imagine why they would not insist that you use their analyzer, so if you bring your own, you are going to be testing twice. In the meantime, virtually no one is testing for CO.

 

[Patti Analox]

I dove about 30 dives over 3 weeks in Bonaire, and I found that I was getting pretty tired by the end of the day. Asleep by 9p kind of tired. I'd take a day off diving, and I'd be just fine again. I always dove well within my NDL, and never had any worrysome pain. Just sleepy.

So, I'm about to do another week of 2-4 dive days, and I currently taking the online PADI Nitrox course. I'm not a big fan of the online training, but, there it is.

I know from reading the board and the course material that I am responsible for making sure the mix shown on the tank is actually in the tank, and I'm pretty clear on why, (1.6 and NDL).

Yet, when I was down in Bonaire, I see the dive shop stack Nitrox tanks outside, with a piece of masking tape on them indicating the mix. The mixes shown varied from 30 to 33%, which told me the tank was probably filled by the partial pressure technique, but that is just a guess.

So, I see people just picking up these tanks, not testing anything, and just driving off. Okay, maybe they tested them later, just before the dive... (I doubt it.):shocked2:

Here is the thing. Do I need to buy a $200+ Gas Analyzer to have in my dive bag, and test all the tanks I pickup, or on the dive boat? Does a shop that does Nitrox fills, offer a analyzer for the public to use?

I'd like to know, who out there owns their own? If you don't own your own, what do you do?

Thanks everyone,

Mortis.

Hi Mortis,

You've already received great advice on your question. At the end of the day, you do not HAVE to own your own analyzer. Would I prefer that you own your own analyzer? You bet! How important is it to you to dive Nitrox? You have options to use the dive boat's analyzer, if it is working and after you wait in line. Or, you can always bum a read off another diver. Both of these options risk (albeit low) you not being able to dive Nitrox because you cannot verify your mix. Diving is about self sufficiency. Gear aquisition is about making choices which support what is important to you. All I ask is that you NEVER dive a tank that has not been analyzed in front of you (by an Analox Analyzer or any other brand). Nitrox is a great benefit to diver safety, but it must be respected.

 

[Bubbletrubble]

What about picking up a nitrox tank that you intend to use with air tables (the added safety - not the deeper/longer benefits)? Do you double check then? Is there a real need to?

Along these same lines...
How many people analyze air fills for O2 percentage?
I think a strong argument can be made to analyze all fills from a shop that pumps air/nitrox/trimix/argon/oxygen.

 

[lv2dive]

Along these same lines...
How many people analyze air fills for O2 percentage?
I think a strong argument can be made to analyze all fills from a shop that pumps air/nitrox/trimix/argon/oxygen.

I analyze all fills bc I'd hate to get what I thought was an air fill, and have it be rich. People make mistakes all the time, and I can improve my odds of being impacted by other people's mistakes by a simple consistent procedure.

...At the end of the day, you do not HAVE to own your own analyzer...You have options to use the dive boat's analyzer, if it is working...Both of these options risk (albeit low) you not being able to dive Nitrox because you cannot verify your mix. Diving is about self sufficiency. Gear aquisition is about making choices which support what is important to you. All I ask is that you NEVER dive a tank that has not been analyzed in front of you (by an Analox Analyzer or any other brand). Nitrox is a great benefit to diver safety, but it must be respected.

One time I have used tanks that I didn't analyze - the boat's analyzer was broken (discovered after we left the dock). I trusted the captain when he said he analyzed them, and in this particular situation, I knew just about every dive op in town banked 30%, so there was very little risk. HOWEVER - After the trip I immediately bought a personal analyzer, and I don't believe that I would make those dives in the same situation today.

 

[EastTNDiver]

I analyze all fills bc I'd hate to get what I thought was an air fill, and have it be rich. People make mistakes all the time, and I can improve my odds of being impacted by other people's mistakes by a simple consistent procedure.


One time I have used tanks that I didn't analyze - the boat's analyzer was broken (discovered after we left the dock). I trusted the captain when he said he analyzed them, and in this particular situation, I knew just about every dive op in town banked 30%, so there was very little risk. HOWEVER - After the trip I immediately bought a personal analyzer, and I don't believe that I would make those dives in the same situation today.

Ever since getting nitrox trained, that's all I have used. However, if I did find myself diving air, I would still analyze my tanks. I am now also looking at purchasing a CO tester, as that would seem to be on the same "trust" level as trusting someone on an O2 mix. As for the OP's question about purchasing their own O2 analyzer, I did for the simple reason that I know when the sensor was last replaced, and how the analyzer has been treated over time. Also, I always analyze onsite pre-dive, and check/set my computer at the same time...safety procedure to which I strictly adhere. Another safety procedure I use, is that if I exit the water, and do not plan to do another dive that day, then I remove the mix/mod tape label before loading my tanks back into the truck...even if I only used half the gas (I dive mostly doubles, so multiple dives on one fill is common for me). That puts my tanks back to an "unknown" state, and ensures that I don't ever trust an old label. I've read accounts of divers getting themselves in trouble for that exact thing.

 

[Oldbear]

While the OP was should or should not purchase an analyzer...I already decided to purchase one. After reading this thread, it is apparent to me for my own reasons and personal safety practices, that that is a good idea.